Dublinoh

Just putting this out there, if your battery is four or five years old, a bad battery can cause esp issues and lots of codes. These cars need good electrical power to keep the computers happy. This solved my esp issue.

g300d

Thanks, yeah I agree, it so happens in this case it really was a mechanical fault.

The ESP code was communication from motor electronics implausible, plus a mechanical supercharger fault. Installing the jumped belt resulted in no more codes and boost again, but a bit less than normal. The lack of boost due to jumped belt probably caused the ESP code, and the mechanical supercharger fault also from the jumped belt. The next day the supercharger pulley sheared from crank hub, was probably slipping before it gave way thus less boost.

Absent suggestions I am looking at all OE parts - crank pulley/harmonic damper assembly, mounting bolt, and will do the front main seal while I'm there. New SC belt and fan belt while I'm at it.